At that price range, be sure to carefully check compatibility for your favorite distribution and for any hardware that you intend to use.

For what it's worth, I have an old HP Stream 7 that currently runs Debian Bookworm. I think that it cost about $100 new. I can use it as a pdf reader and to sync files, but there are plenty of tradeoffs due to the 1gb of RAM, the weak Atom processor, the small amount of built-in storage, the mediocre touchscreen, and the general poor quality of touchscreen interfaces among low-resource window managers. Neither camera works and several distributions can't support the built-in audio. Screen rotation is a crapshoot. Forget about low-power standby. Some of these issues are unique to my tablet, but some of them are problems that people tend to run into when they try to shoehorn linux into a tablet that wasn't built with linux in mind. Something like a Pinetab would be a better bet.

I saw another person suggest an aftermarket Surface. If you go this route, carefully research the exact model number to verify that the hardware supports linux and that there is a clean way of installing your preferred distribution.

Another thing worth mentioning. Installing linux can be a special kind of hell. Most distributions don't have a touchscreen-friendly installer. For my cheap tablet, this meant cobbling together a flash drive, a powered USB hub, a USB keyboard, a USB ethernet adapter, and a USB-OTG cable for the single micro-usb port on the tablet. Then, I had to race the decade-old tablet battery to the finish line during the install process. Plus something about a 32-bit EFI bootloader combined with a 64-bit processor.